/*

*

* Bluetooth HCI UART driver

*

* Copyright (C) 2000-2001 Qualcomm Incorporated

* Copyright (C) 2002-2003 Maxim Krasnyansky <maxk@qualcomm.com>

* Copyright (C) 2004-2005 Marcel Holtmann <marcel@holtmann.org>

*

*

* This program is free software; you can redistribute it and/or modify

* it under the terms of the GNU General Public License as published by

* the Free Software Foundation; either version 2 of the License, or

* (at your option) any later version.

*

* This program is distributed in the hope that it will be useful,

* but WITHOUT ANY WARRANTY; without even the implied warranty of

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

* GNU General Public License for more details.

*

* You should have received a copy of the GNU General Public License

* along with this program; if not, write to the Free Software

* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

*

*/

#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/init.h>

#include <linux/types.h>

#include <linux/fcntl.h>

#include <linux/interrupt.h>

#include <linux/ptrace.h>

#include <linux/poll.h>

#include <linux/slab.h>

#include <linux/tty.h>

#include <linux/errno.h>

#include <linux/string.h>

#include <linux/signal.h>

#include <linux/ioctl.h>

#include <linux/skbuff.h>

#include <net/bluetooth/bluetooth.h>

#include <net/bluetooth/hci_core.h>

#include "hci_uart.h"

#define VERSION "2.2"

static struct hci_uart_proto *hup[HCI_UART_MAX_PROTO];

int hci_uart_register_proto(struct hci_uart_proto *p)

{

if (p->id >= HCI_UART_MAX_PROTO)

return -EINVAL;

if (hup[p->id])

return -EEXIST;

hup[p->id] = p;

return 0;

}

int hci_uart_unregister_proto(struct hci_uart_proto *p)

{

if (p->id >= HCI_UART_MAX_PROTO)

return -EINVAL;

if (!hup[p->id])

return -EINVAL;

hup[p->id] = NULL;

return 0;

}

static struct hci_uart_proto *hci_uart_get_proto(unsigned int id)

{

if (id >= HCI_UART_MAX_PROTO)

return NULL;

return hup[id];

}

static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)

{

struct hci_dev *hdev = hu->hdev;

/* Update HCI stat counters */

switch (pkt_type) {

case HCI_COMMAND_PKT:

hdev->stat.cmd_tx++;

break;

case HCI_ACLDATA_PKT:

hdev->stat.acl_tx++;

break;

case HCI_SCODATA_PKT:

hdev->stat.sco_tx++;

break;

}

}

static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)

{

struct sk_buff *skb = hu->tx_skb;

if (!skb)

skb = hu->proto->dequeue(hu);

else

hu->tx_skb = NULL;

return skb;

}

int hci_uart_tx_wakeup(struct hci_uart *hu)

{

struct tty_struct *tty = hu->tty;

struct hci_dev *hdev = hu->hdev;

struct sk_buff *skb;

if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state)) {

set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);

return 0;

}

BT_DBG("");

restart:

clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);

while ((skb = hci_uart_dequeue(hu))) {

int len;

set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);

len = tty->ops->write(tty, skb->data, skb->len);

hdev->stat.byte_tx += len;

skb_pull(skb, len);

if (skb->len) {

hu->tx_skb = skb;

break;

}

hci_uart_tx_complete(hu, bt_cb(skb)->pkt_type);

kfree_skb(skb);

}

if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state))

goto restart;

clear_bit(HCI_UART_SENDING, &hu->tx_state);

return 0;

}

static void hci_uart_init_work(struct work_struct *work)

{

struct hci_uart *hu = container_of(work, struct hci_uart, init_ready);

int err;

if (!test_and_clear_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))

return;

err = hci_register_dev(hu->hdev);

if (err < 0) {

BT_ERR("Can't register HCI device");

hci_free_dev(hu->hdev);

hu->hdev = NULL;

hu->proto->close(hu);

}

set_bit(HCI_UART_REGISTERED, &hu->flags);

}

int hci_uart_init_ready(struct hci_uart *hu)

{

if (!test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))

return -EALREADY;

schedule_work(&hu->init_ready);

return 0;

}

/* ------- Interface to HCI layer ------ */

/* Initialize device */

static int hci_uart_open(struct hci_dev *hdev)

{

BT_DBG("%s %p", hdev->name, hdev);

/* Nothing to do for UART driver */

set_bit(HCI_RUNNING, &hdev->flags);

return 0;

}

/* Reset device */

static int hci_uart_flush(struct hci_dev *hdev)

{

struct hci_uart *hu = hci_get_drvdata(hdev);

struct tty_struct *tty = hu->tty;

BT_DBG("hdev %p tty %p", hdev, tty);

if (hu->tx_skb) {

kfree_skb(hu->tx_skb); hu->tx_skb = NULL;

}

/* Flush any pending characters in the driver and discipline. */

tty_ldisc_flush(tty);

tty_driver_flush_buffer(tty);

if (test_bit(HCI_UART_PROTO_SET, &hu->flags))

hu->proto->flush(hu);

return 0;

}

/* Close device */

static int hci_uart_close(struct hci_dev *hdev)

{

BT_DBG("hdev %p", hdev);

if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))

return 0;

hci_uart_flush(hdev);

hdev->flush = NULL;

return 0;

}

/* Send frames from HCI layer */

static int hci_uart_send_frame(struct sk_buff *skb)

{

struct hci_dev* hdev = (struct hci_dev *) skb->dev;

struct hci_uart *hu;

if (!hdev) {

BT_ERR("Frame for unknown device (hdev=NULL)");

return -ENODEV;

}

if (!test_bit(HCI_RUNNING, &hdev->flags))

return -EBUSY;

hu = hci_get_drvdata(hdev);

BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type, skb->len);

hu->proto->enqueue(hu, skb);

hci_uart_tx_wakeup(hu);

return 0;

}

/* ------ LDISC part ------ */

/* hci_uart_tty_open

*

* Called when line discipline changed to HCI_UART.

*

* Arguments:

* tty pointer to tty info structure

* Return Value:

* 0 if success, otherwise error code

*/

static int hci_uart_tty_open(struct tty_struct *tty)

{

struct hci_uart *hu;

BT_DBG("tty %p", tty);

/* Error if the tty has no write op instead of leaving an exploitable

hole */

if (tty->ops->write == NULL)

return -EOPNOTSUPP;

if (!(hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL))) {

BT_ERR("Can't allocate control structure");

return -ENFILE;

}

tty->disc_data = hu;

hu->tty = tty;

tty->receive_room = 65536;

INIT_WORK(&hu->init_ready, hci_uart_init_work);

spin_lock_init(&hu->rx_lock);

/* Flush any pending characters in the driver and line discipline. */

/* FIXME: why is this needed. Note don't use ldisc_ref here as the

open path is before the ldisc is referencable */

if (tty->ldisc->ops->flush_buffer)

tty->ldisc->ops->flush_buffer(tty);

tty_driver_flush_buffer(tty);

return 0;

}

/* hci_uart_tty_close()

*

* Called when the line discipline is changed to something

* else, the tty is closed, or the tty detects a hangup.

*/

static void hci_uart_tty_close(struct tty_struct *tty)

{

struct hci_uart *hu = (void *)tty->disc_data;

struct hci_dev *hdev;

BT_DBG("tty %p", tty);

/* Detach from the tty */

tty->disc_data = NULL;

if (!hu)

return;

hdev = hu->hdev;

if (hdev)

hci_uart_close(hdev);

if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) {

if (hdev) {

if (test_bit(HCI_UART_REGISTERED, &hu->flags))

hci_unregister_dev(hdev);

hci_free_dev(hdev);

}

hu->proto->close(hu);

}

kfree(hu);

}

/* hci_uart_tty_wakeup()

*

* Callback for transmit wakeup. Called when low level

* device driver can accept more send data.

*

* Arguments: tty pointer to associated tty instance data

* Return Value: None

*/

static void hci_uart_tty_wakeup(struct tty_struct *tty)

{

struct hci_uart *hu = (void *)tty->disc_data;

BT_DBG("");

if (!hu)

return;

clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);

if (tty != hu->tty)

return;

if (test_bit(HCI_UART_PROTO_SET, &hu->flags))

hci_uart_tx_wakeup(hu);

}

/* hci_uart_tty_receive()

*

* Called by tty low level driver when receive data is

* available.

*

* Arguments: tty pointer to tty isntance data

* data pointer to received data

* flags pointer to flags for data

* count count of received data in bytes

*

* Return Value: None

*/

static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data, char *flags, int count)

{

struct hci_uart *hu = (void *)tty->disc_data;

if (!hu || tty != hu->tty)

return;

if (!test_bit(HCI_UART_PROTO_SET, &hu->flags))

return;

spin_lock(&hu->rx_lock);

hu->proto->recv(hu, (void *) data, count);

if (hu->hdev)

hu->hdev->stat.byte_rx += count;

spin_unlock(&hu->rx_lock);

tty_unthrottle(tty);

}

static int hci_uart_register_dev(struct hci_uart *hu)

{

struct hci_dev *hdev;

BT_DBG("");

/* Initialize and register HCI device */

hdev = hci_alloc_dev();

if (!hdev) {

BT_ERR("Can't allocate HCI device");

return -ENOMEM;

}

hu->hdev = hdev;

hdev->bus = HCI_UART;

hci_set_drvdata(hdev, hu);

hdev->open = hci_uart_open;

hdev->close = hci_uart_close;

hdev->flush = hci_uart_flush;

hdev->send = hci_uart_send_frame;

SET_HCIDEV_DEV(hdev, hu->tty->dev);

if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))

set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);

if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))

set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);

if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))

hdev->dev_type = HCI_AMP;

else

hdev->dev_type = HCI_BREDR;

if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))

return 0;

if (hci_register_dev(hdev) < 0) {

BT_ERR("Can't register HCI device");

hci_free_dev(hdev);

return -ENODEV;

}

set_bit(HCI_UART_REGISTERED, &hu->flags);

return 0;

}

static int hci_uart_set_proto(struct hci_uart *hu, int id)

{

struct hci_uart_proto *p;

int err;

p = hci_uart_get_proto(id);

if (!p)

return -EPROTONOSUPPORT;

err = p->open(hu);

if (err)

return err;

hu->proto = p;

err = hci_uart_register_dev(hu);

if (err) {

p->close(hu);

return err;

}

return 0;

}

/* hci_uart_tty_ioctl()

*

* Process IOCTL system call for the tty device.

*

* Arguments:

*

* tty pointer to tty instance data

* file pointer to open file object for device

* cmd IOCTL command code

* arg argument for IOCTL call (cmd dependent)

*

* Return Value: Command dependent

*/

static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file * file,

unsigned int cmd, unsigned long arg)

{

struct hci_uart *hu = (void *)tty->disc_data;

int err = 0;

BT_DBG("");

/* Verify the status of the device */

if (!hu)

return -EBADF;

switch (cmd) {

case HCIUARTSETPROTO:

if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {

err = hci_uart_set_proto(hu, arg);

if (err) {

clear_bit(HCI_UART_PROTO_SET, &hu->flags);

return err;

}

} else

return -EBUSY;

break;

case HCIUARTGETPROTO:

if (test_bit(HCI_UART_PROTO_SET, &hu->flags))

return hu->proto->id;

return -EUNATCH;

case HCIUARTGETDEVICE:

if (test_bit(HCI_UART_PROTO_SET, &hu->flags))

return hu->hdev->id;

return -EUNATCH;

case HCIUARTSETFLAGS:

if (test_bit(HCI_UART_PROTO_SET, &hu->flags))

return -EBUSY;

hu->hdev_flags = arg;

break;

case HCIUARTGETFLAGS:

return hu->hdev_flags;

default:

err = n_tty_ioctl_helper(tty, file, cmd, arg);

break;

}

return err;

}

/*

* We don't provide read/write/poll interface for user space.

*/

static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,

unsigned char __user *buf, size_t nr)

{

return 0;

}

static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,

const unsigned char *data, size_t count)

{

return 0;

}

static unsigned int hci_uart_tty_poll(struct tty_struct *tty,

struct file *filp, poll_table *wait)

{

return 0;

}

static int __init hci_uart_init(void)

{

static struct tty_ldisc_ops hci_uart_ldisc;

int err;

BT_INFO("HCI UART driver ver %s", VERSION);

/* Register the tty discipline */

memset(&hci_uart_ldisc, 0, sizeof (hci_uart_ldisc));

hci_uart_ldisc.magic = TTY_LDISC_MAGIC;

hci_uart_ldisc.name = "n_hci";

hci_uart_ldisc.open = hci_uart_tty_open;

hci_uart_ldisc.close = hci_uart_tty_close;

hci_uart_ldisc.read = hci_uart_tty_read;

hci_uart_ldisc.write = hci_uart_tty_write;

hci_uart_ldisc.ioctl = hci_uart_tty_ioctl;

hci_uart_ldisc.poll = hci_uart_tty_poll;

hci_uart_ldisc.receive_buf = hci_uart_tty_receive;

hci_uart_ldisc.write_wakeup = hci_uart_tty_wakeup;

hci_uart_ldisc.owner = THIS_MODULE;

if ((err = tty_register_ldisc(N_HCI, &hci_uart_ldisc))) {

BT_ERR("HCI line discipline registration failed. (%d)", err);

return err;

}

#ifdef CONFIG_BT_HCIUART_H4

h4_init();

#endif

#ifdef CONFIG_BT_HCIUART_BCSP

bcsp_init();

#endif

#ifdef CONFIG_BT_HCIUART_LL

ll_init();

#endif

#ifdef CONFIG_BT_HCIUART_ATH3K

ath_init();

#endif

#ifdef CONFIG_BT_HCIUART_3WIRE

h5_init();

#endif

return 0;

}

static void __exit hci_uart_exit(void)

{

int err;

#ifdef CONFIG_BT_HCIUART_H4

h4_deinit();

#endif

#ifdef CONFIG_BT_HCIUART_BCSP

bcsp_deinit();

#endif

#ifdef CONFIG_BT_HCIUART_LL

ll_deinit();

#endif

#ifdef CONFIG_BT_HCIUART_ATH3K

ath_deinit();

#endif

#ifdef CONFIG_BT_HCIUART_3WIRE

h5_deinit();

#endif

/* Release tty registration of line discipline */

if ((err = tty_unregister_ldisc(N_HCI)))

BT_ERR("Can't unregister HCI line discipline (%d)", err);

}

module_init(hci_uart_init);

module_exit(hci_uart_exit);

MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");

MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);

MODULE_VERSION(VERSION);

MODULE_LICENSE("GPL");

MODULE_ALIAS_LDISC(N_HCI);